A 9P error past 128 bytes keeps its reason: the path in it gives up its middle to …

An Rerror carries 128 bytes (Plan 9's ERRMAX) and the engine cut longer text there, and a builtin's failure was first clipped between words to 256 with ...: either way the end, which says why, was what went. tree.handle now fits a long reason by cutting the middle of its longest path, else of the whole text, on a character boundary, and reportFailure fills its buffer the same way.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 9 deletions

diff --git a/src/Messages.zig b/src/Messages.zig
index 7342f726..42200863 100644
--- a/src/Messages.zig
+++ b/src/Messages.zig
@@ -503,18 +503,14 @@ pub fn clip(text: []const u8, max: usize) []const u8 {
 /// reportError with the words already chosen.
 pub fn reportFailure(p: *Pardes, id: usize, text: []const u8) void {
     p.fs.failures +%= 1;
-    // A builtin a ctl write runs: its first error is also the write's, cut
-    // between words.
+    // A builtin a ctl write runs: its first error is also the write's, its
+    // path shortened in the middle if it must be, never its reason.
     const failing_write = p.fs.no_prompt or p.fs.capturing or p.fs.write_waits;
     if (failing_write and p.fs.failure_len == 0) {
-        const kept = if (text.len > p.fs.failure.len) clip(text, p.fs.failure.len - 3) else text;
+        var room: @TypeOf(p.fs.failure) = undefined;
+        const kept = pardes.ctlfs.fitErr(text, &room);
         @memcpy(p.fs.failure[0..kept.len], kept);
-        var n = kept.len;
-        if (kept.len < text.len) {
-            @memcpy(p.fs.failure[n..][0..3], "...");
-            n += 3;
-        }
-        p.fs.failure_len = @intCast(n);
+        p.fs.failure_len = @intCast(kept.len);
     }
     // The write fails with it, and its err record says it: no msg for it,
     // so the same failure again is the same record again, counted